The present invention relates to voltage measuring devices and particularly to apparatus for monitoring the voltage on an AC high voltage overhead transmission line.
In commonly assigned U.S. Pat. No. 4,384,289 there is disclosed a transponder unit which can be clamped at any point on an AC high voltage overhead transmission line for the purpose of generating real time data indicative of the line's temperature and the current flowing through it. This data is extremely useful to utilities in protecting the lines from protracted overloading and thus to insure long conductor life. Often it is not the generating plant but the size and type of transmission line conductors linking the plant to the substation that limit the amount of power that can be delivered without jeopardizing conductor life.
While transmission line temperature and current readings provide important information, it would be quite desirable to also know the transmission line voltage at the same monitoring point. From instantaneous current and voltage readings, the power being delivered over the transmission line can be ascertained. Once these three factors are known, the power factor can be determined. Since utilities are in the business of selling power, a continuous reading of the amount of power being dispatched over a transmission line provides highly useful information.
It is accordingly an object of the present invention to provide apparatus for continuously monitoring the voltage at any desired point along an aerial H.V. transmission line.
A further object is to provide transmission line voltage monitoring apparatus of the above-character which is simple in construction, easy to implement, and accurate and reliable in operation.
Other objects of the invention will, in part, be obvious and, in part, appear hereinafter.